Folding apparatus for narrow paper

Abstract

A zig-zag folding apparatus which includes a swing chute movable in a forward and rearward direction to transmit narrow sheet material between spaced, forward and rearward folding stations. A sheet folding device is located at each of the folding stations which includes a chain carrying a series of paddles, and a drive train which rotates the chain and paddles with respect to the folding station. In the course of moving in a forward and rearward direction, the swing chute transmits the narrow sheet material into contact with beaters or knock-down fingers located at each folding station which direct the sheet into a folding position where the paddles carried by the chain operate to fold or crease the sheet material along its perforations and thus form a stack of zig-zag folded sheets.

I claim: 
     
       1. Apparatus for zig-zag folding a length of paper having longitudinally spaced, transversely oriented perforations, comprising: a frame having forward and rearward ends, opposed sides and a main drive shaft;   a swing chute which receives the length of paper, said swing chute being drivingly connected to said main drive shaft for movement in a forward and rearward direction between spaced first and second folding stations;   sheet folding device located at each of said first and second folding stations, each of said sheet folding devices including: (i) a drive sprocket and at least one idler sprocket;   (ii) an endless chain connected to said drive sprocket and to said at least one idler sprocket, said endless chain mounting a number of spaced paddles and being effective to move said paddles with respect to one of said first and second folding stations between a substantially vertical folding position and a substantially horizontal folding position;   (iii) a series of interconnected gears, one of said gears being drivingly connected to said main drive shaft and another of said gears being directly connected to said drive sprocket, said series of interconnected gears being effective to control the speed of rotation of said drive sprocket to provide a delay in the movement of each of said paddles upon reaching said substantially vertical folding position, and to then rapidly move each of said paddles from said substantially vertical folding position to said substantially horizontal folding position.     
     
     
       2. The apparatus of claim 1 in which each of said paddles has a tip and a base which mounts to said chain, each of said paddles progressively increasing in thickness from said tip to said base thereof. 
     
     
       3. The apparatus of claim 1 in which said series of interconnected gears includes a first gear and a second gear which are interconnected such that the center of said first gear is offset from the center of said second gear, said first and second gears being rotatable about a common axis of rotation. 
     
     
       4. The apparatus of claim 1 further including means for adjusting the relative position of each of said sheet folding device, in a forward and rearward direction, to vary the distance between said first and second folding stations.